Fuse



Feb. 24, 1931. M L WARNER 1,794,045

FUSE

Filed June 13, l928 Fig J.

.#1 TTORNEYS Patented Feb. 24, 1931 UNITED STATES PATENT OFFICE MAURICE LEE WARNER, 0F DOVER, OHIO, ASSIGNOR TO DOVER MANUFACTURING COMPANY, OF DOVER, OHIO, A CORPORATION OF OHIOy FUSE Application led J'une 13, 1928.v *Serial No. 284,899.

This invention relates to improvements in fuses. The fuse herein disclosed is particularly adapted for use in connection with electrical ap liances such as percolators or the like but lrias other utility as will be obvious from the disclosure.

It is the object of the invention to provide a novel and sim le form of fusible element and mounting t erefor which can be easily and economically manufactured and whic is adapted for ready manipulation and replacement by inexperienced persons.

More specifically stated, it is my urpose to provide a fusible element in the orm of the shank of a spool, the spool heads being made of brass or some other material adapted to give better contact than is ossible in the use of the fusible material. his spool is adapted to be inserted to operate a cap between two resiliently separable spring arms in series with the current supplied to a heating element so that if the spool melts the arms will separate and the current will be interrupted. Such a device as this may be made to operate whenever a percolator or like heating appliance boils dry, thereby saving much dama e to the percolator. Because of the tact t at the circumstances which ive rise to the melting of the fuse may occur requently, it is a purpose of this invention to make the fuse ve easily replaceable and this is' accomplishe by the design of the spool-shaped fuse member and by the springs which are formed with slots readily adapted to receive the shank of the spool.

In the drawings,-

Figure 1 is a side elevation of a percolator havin its skirt portion broken away to expose the electrical contact mechanism;

Figure 2 is a plan view of the bottom of the percolator shown in Figure 1 illustrating the application of a fuse and fuse mounting of this invention to the contact mechanism;

Figure 3 is an enlarged detail partially in axial section of the support for the fuse mounting on the contact mechanism;

Figure 4 is an enlarged detail in side elevation of one of the resilient fuse mounting arms;

Figure 5 is an enlarged detail in axial section of the fuse unit.

Like parts are identified by similar reference characters throughout the several views.

The percolator comprises a receptacle 6 having a skirt portion 7 spanned by a bar 8 from which the pressurev screws 9 support heating element 10. A mounting plate 11 attached to the heating element is rovided with a depending bracket 12 in w ich the terminal posts 15 and 16 are supported for revistry with the plug receiving member 17.

Fach of the terminal posts 15 and 16 is insulated from the bracket member 12 by suitable di-electric Washers 18. Terminal post 16 may be connected directly to the heating element by means of a conductor 19, as shown in Fi 2. Terminal post 15 carries the fuse and use mounting hereinafter to be described.

The fuse mounting comprises a pair of spaced spring arms 2O and 21 which tend reslliently to separate and to assume the ositions indicated by the dotted lines in F 1g. 2. Spring arm 20 is mounted directl uponthe terminal post 15 on the inside of bracket 12, as shown in Fig. 3. A di-electric spacer 23 is provided at 24 with a boss upon which spring arm 21 is mounted. The conducting lead 25 to the heating element is in direct contact witlispring arm 21 and is held lin pressure engagement therewith by means of nut 26 and di-electrie washer 27. Itwill be obvious, therefore, that sprin arms 2O and 21 are insulated from each ot er andare connected respectively with the sourceof current supply and with the heating element.

During normal operation of. the device, an elect-rica connection is established between spring arms 20 and 21 by means of the fuse element shown in detail in Fig. 5. As sugested above, this element comprises two rass or copper heads 30 counter-sunk at 31. The fusible material is made lin the form of a shank or spindle 32 which connects'heads 30 and is riveted in the counter-sunk recesses 31, as shown in Fig. 5. Each ofthe s ring arms 20 and 21 is provided at 33 with av ownwardl; and rearwardly opening slot Iinto which the s ank or spindle portion 32 of the spoolshaped fuse element is receivable.- The length of such shank or spindle portion is such that when the fuse is in place the spring arms 2() and 21 will be substantially parallel and are thereby enabled to make face contact with the heads 30 of the fuse element. The fact that such heads are of some excellent conducting material such as brass, bronze, or copper, insures the establishment of a good contact through the fuse device. It is found that the soft fusible material does not ordinarily make an adequate contact.

The fuse is secured against displacement from its proper position not only by the downward direction and by the curvature of the slots 33 but also by means of the spring tension of arms 20 and 21 which is customarily exerted against the heads 30 to maintain a frictional resistance against displacement Upon such occasions as the fuse requires renewal, however, it is an extremely easy matter to press the spring arms 20 and 21 together and to introduce a new fuse element into the slots 33 thereof.

It may be noted that the fact that the fuse mounting subjects the fuse to tension rather than to compression has been found to result in great dependability of operation. There is little or nol possibility that any part of the fuse may lodge between the mounting arms in such a way as to maintain a current after the device becomes overheate'd. It is found that the temperatures at which this device will operate may be predetermined with considerable accuracy so that Ain any case in which the receptacle 6 is empty while current is supplied to the terminal posts 15 and 16 the resulting heat will, with certainty, melt the link 32 to break the electrical connection to the heating element.

The spring arms 20 and 21 project from the mounting near the center of the percolator to a position such that the fuse is held in close proximity to the skirt portion 7 thereof. It is found that when a percolator boils dry and becomes over-heated the temperature of the skirt portion will rise very rapidly and due to the location of the fuse in this device it will be more sensitive to such rise of temperature than would be the case if it were located elsewhere.

I claim 1. In a device of the character described, the combination with a mounting plate and terminal posts thereon, of a heating element, a receptacle above said velement provided with a skirt surrounding said element and mounting plate, and a pair of arms supported from said mounting plate and projecting toward aportion of said skirt whereby to be adapted to receive heat therefrom, and afusible link connecting said arms adjacent said skirt, one of said arms being in electrical connection with said heating element and the other of said arms being in electrical connection with one of said posts and insulated from said first mentioned arm savefor said link.

2. In a device of the character described, the combination with a receptacle having a skirt portion subject to an increase of heat when said receptacle is overheated, .a heating element beneath said receptacle and within said skirt, a terminal post and a fuse mounting connected in series between said terminal post and element, and comprising a pair of arms projecting from said post toward said skirt and a fusible link replaceably carried by said arms adjacent said skirt.

3. In a device of the character described, the combination with a receptacle having a skirt portion subject to an increase of heat when said receptacle is overheated, a heating element beneath said receptacle and within said skirt, a terminal post and a fuse mounting connected in series between said terminal post and element, and comprising a pair of arms projecting toward said skirt, and a fusible link replaceably carried by said arms adjacent said skirt, said arms being resiliently separable and said link being provided with heads adapted normally to restrain said arms against separation.

4. In a device of the character described, the combination with a receptacle having a skirt portion subject to an increase of heat when said receptacle is overheated, a heatmg element beneath said receptacle and within said skirt, a terminal' post and a fuse mounting connected in series between said terminal post and element, and comprising a pair of arms projecting toward said skirt. and a fusible link replaceably carried by said arms adjacent said skirt, said arms being supported in mutually spaced relation at their inner ends and lresiliently separable at their outer ends, and said link being provided with non-fusible heads exteriorly contacting with said arms and adapted to restrain them against separation at their outer ends.

5. In a device of the. character described, the combination with a receptacle having a skirt portion subject to an increase of heat when said receptacle is overheated, a heating element beneath said receptacle and within said skirt, a terminal post,and a fuse mounting connected in series between said terminal post and element, and comprising a pair of arms projecting toward said skirt, and a fusible link replaceably carried by said arms adjacent said skirt, said arms being resiliently separable at the ends adjacent the skirt and being provided with upwardly opening slots adjacent said ends, and said link comprising a spool-shaped element havi-ng relatively non-fusible heads engaging said arms, and a shank portion receivable in said slots and provided with a fusible part.

MAURICE LEE WARNER. 

